The Portland Timbers advanced to their second MLS Western Conference final in franchise history with a 2–0 win over the Vancouver Whitecaps on Sunday. The slim victory gave Portland an aggregate win by the same score in the series after a goalless draw a week earlier.

Fanendo Adi, Portland’s top goal-getter and single-season MLS record goalscorer, put away the first goal after 31 minutes. Following an interchange of passes between Rodney Wallace and Diego Valeri on the left, Valeri found Adi with a cutback cross from the endline for a left-footed shot into the roof of the net.

Diego Chará finished it off in the fourth minute of stoppage time, as Vancouver pressed for an equalizer. He took Adi’s square pass in the penalty area and side-footed it easily past Whitecaps goalkeeper David Ousted.

That sealed Portland’s only victory of the season over Vancouver in a five-match series that could hardly separate the teams. With the victory, the Timbers move onto the Western Conference final against FC Dallas, starting in a couple weeks.

Here are three thoughts on the culmination of a tight series between Cascadia rivals:

These teams offer perfectly contrasting styles

Part of the reason the season series between the Whitecaps and Timbers finished dead even—one win each and three draws with a 4–3 combined score in Portland’s favor—was the way the teams match up in terms of their playing styles. Portland’s possession game and Vancouver’s counterattacks meant each was better than the other in contrasting ways, leading to multiple stalemates.

Being at home made no difference for the Whitecaps over the majority of the season, as they finished 9-6-2 at B.C. Place for the worst record among playoff teams in their own stadium, while their 7-7-3 mark away from home was the best in MLS. Carl Robinson’s young team made major strides in 2015, but it wasn’t a spectacular home team because it had trouble carrying the game.

That was easily apparent from the start again on Sunday. Portland dictated play for much of the game, and Vancouver tried to pick the ball off and go forward in a hurry. The Timbers scoring first became an insurmountable challenge because the home team would have had to score twice, which it couldn’t do once in 2015 after conceding first, finishing with a 0-11-2 record when allowing the first goal.

Manneh’s injury was the turning point

Vancouver’s game plan took a major hit when Kekuta Manneh left the game with a left ankle injury. A nasty twist on the turf left him unable to continue, and nobody on the field could match his pace after he left. Octavio Rivero became a very lonely man, often without support when he managed to latch onto his teammates’ long balls out of the back.

The Whitecaps continued sitting deep and trying to spring quick counters, even without Manneh and even after Adi scored just over half an hour in. Mauro Rosales gave the team a boost in experience, but that youth and unpredictability is what made Manneh such a dangerous contributor all season, and Vancouver sorely missed it.

The Whitecaps were always going to struggle to exert any control over the match with that style of play, especially as the desperate team playing a goal down. Caleb Porter’s men remained composed, knowing they would be numbers-up nearly every time Rivero received a launched clearance. The defenders won it coolly and played out of the minimal pressure, sending the ball straight back to the other end of the field.

Yellow-card accumulation rearing its head for Portland

The Timbers have played three games to Dallas’s two in the playoffs, so it’s not a huge surprise that some players would pick up a couple bookings in the intense matches they’ve had. The architects of Portland’s goal, Wallace and Valeri, will be suspended for the first leg, and starting left back Jorge Villafaña could also be out if the injury he picked up in the second half is serious enough.

The rules could certainly be more lenient because as it stands, two yellow cards in four games would still mean a player is suspended for a crucial playoff match if his team had to go through the knockout round. The accumulation resets heading into the MLS Cup final, but getting there will now be more difficult for Portland without a couple of its usual starters.

This team has shown that it can play through difficult situations in the postseason, though. The draw at home in the first leg against Vancouver that followed a crazy 11-round shootout win three days earlier set the Timbers up well for the away match, and they followed through on that window of opportunity.

It’ll take something similar, as they play at home first against Dallas on Nov. 22, to advance to their first MLS Cup final. It’s a task that seems far from impossible for Porter’s men considering their recent form.